The invention relates generally to suturing and relates more particularly to suturing in which it is desired to suture a layer of tissue without puncturing or damaging another layer of tissue.
It is well known to suture tissue, for example to close wounds and incisions in living tissue. Some historical background of suturing is found in PCT appl. no. PCT/US00/29508, filed Oct. 26, 2000, designating the United States, published as PCT publication no. WO 01/30245, published May 3, 2001 and assigned to the same assignee as the assignee of the present application, incorporated herein by reference.
One goal in suturing is to bring two tissue edges together by means of the sutures. It is also typically desired that the sutures not puncture a deeper tissue. It is also typically desired that the points at which the sutures puncture the tissue be in a particular relationship with the tissue edges. For example, it is typically desired that the points not be too close to the edges. Competing with the latter goal is the previously mentioned goal that the suture not puncture the deeper tissue.
It is also known to perform a series of sutures with the assistance of a helical suture device such as that set forth in the above-mentioned PCT application designating the United States. With such a helical suture device, it is necessary to draw some balance between large and small diameters. If the diameter is too small, the punctures may be undesirably close to the edges of the tissue being sutured. If the diameter is too large, there is the concern that the suture device may undesirably pierce the tissue below. It would thus be extremely desirable if a way could be devised in which a helical suture device could be employed to suture tissue, while minimizing the risk that the device may puncture tissue below.